Sealing apparatus

ABSTRACT

Sealing apparatus for pressure vessels including a resilient seal ring disposed in a receptacle secured to the vessel. The seal ring has an outer lip and an inwardly turned flange angularly disposed to the outer lip whereby pressure within the vessel is exerted through an opening in the seal ring to urge the seal ring into positive sealing relation with outer surfaces of the vessel around an opening in the vessel and with surfaces in the receptacle. The seal ring carries a seal member positionable through an opening in the vessel having surfaces urged by fluid pressure in the vessel into sealing engagement with surfaces inside the vessel.

0 ,1 z 7 Unite States atet 1 1 1 1 Kemp Oct. 16, 1973 SEALING APPARATUSPrimary Examiner-George T. Hall [76] Inventor: Norman H. Kemp, 2609Manona Attorney-Howard Moore et Dr., Dallas, Tex. 75220 [22] Filed: Mar.6, 1972 [57] ABSTRACT Sealing apparatus for pressure vessels including aresil- [21] Appl' 232,107 ient seal ring disposed in a receptaclesecured to the Related us, Application Data vessel. The seal ring has anouter lip and an inwardly 63 I turned flange angularly disposed to theouter lip I l z sfi g i gi gg g whereby pressure within the vessel isexerted through Mayw, 1968, Pat. 3,498,493 j an opening in the seal ringto urge the seal ring into tion-in-part of Ser. No. 494,061, Pat. No.3,387,738, positive sealing relation with outer surfaces of the vesselaround an opening in the vessel and with surfaces [52 us. (:1 220/46 R,138/90, 166/118 in the receptacle The seal ring carries a seal member 51Int. c1 865d 53/00 positionable through an opening in the vessel having[58] Field of Search 220/46 R, 55; Surfaces urged by fluid Pressure inthe Vessel into seal- 138/90; 1 1 1 ing engagement with surfaces insidethe vessel.

[56] References Cited UNITED STATES PATENTS 17 Cla1ms, 8 Drawing Flgures3,647,108 3/1972 Kemp 220/46 R 3,498,493 3/1970 Kemp 220/46 R 1 SEALINGAPPARATUS This is a continuation-in-part of my copendlng Pat.application Ser. No. 22, filed January 2, 1969, entitled Closure forPressure Vessels which was a continuation-in-part of Patent ApplicationSer. No. 729,966, filed May 17, 1968, entitled CLOSURE FOR PRES- SUREVESSELS, now US. Pat. No. 3,498,493 which is a continuation-in-part ofPatent Application Ser. No. 494,061, filed Oct. 8, 1965, entitledCLOSURE SEAL", now U.S. Pat. No. 3,387,738.

BACKGROUND OF INVENTION The apparatus disclosed in the aforementionedapplications offers significant improvements over sealing apparatusheretofore developed. The apparatus disclosed therein generally relatesto a seal ring made of resilient material having an outer lip andinwardly extending flange angularly disposed with reference to the outerlip such that the seal ring, which is slidably disposed in a receptaclehaving an annular skirt, may be positioned about an opening. Fluidpressure exerted through the opening urges the flange ofthe seal ringdownwardly to seal about the opening, while urging the annular lipoutwardly to seal against the skirt of the receptacle.

Pressure vessels, such as tanks and pipe lines for storing andtransporting liquids and gases under pressure must meet certainstandards, as specified by regulatory authorities and users as tointernal pressure as to which they can be subject without rupturing orleaking, inasmuch as many of the liquids and gases stored andtransported therein are of volatile, noxious, flamable, and explosivecharacter. Such internal pressure tests, often made in pressure rangesto double the desired working pressure of the vessel, must be carriedout by the manufacturer as a safety precaution, to comply with the rulesof regulatory authorities and to meet the requirements of carriers andusers.

Prior to development of the invention described in the aforementionedpatents, difficulty had been encountered in carrying out such testingoperations due to the difficulty of properly sealing the opening oropenings in the tank, pipe, or other container during such testingoperations and in carrying out inspection tests to see that theprescribed standards were maintained after installation.

The apparatus disclosed in the aforementioned patents is very effectivefor sealing openings in pressure vessels, such as tanks and pipes. Theapparatus employs a differential area principle wherein the area of asealing element against which pressure in the vessel acts is less thanthe area of the sealing element upon whichpressure in a receptaclesecured to the vessel acts. Since equal fluid pressure acts upon each ofthe surfaces, the sealing element is urged by the pressure into sealingengagement with the vessel.

However, since the sealing element employed to seal the end of a pipewas urged against end surfaces of the pipe, pipe having rough ends wasdifficult to seal and sometimes damaged the sealing element.

The problems encountered in carrying out periodic inspection of pressurevessels are so similar to those encountered in testing that thedescription will be directed primarily to testing operations. However,it should be noted that the use of the embodiments of the closure andseal hereinafter described is not restricted to testing operations.

SUMMARY OF INVENTION I have developed an improved sealing apparatus forpressure vessels comprising the combination of a seal ring receptacleand a seal ring assembly slidably disposed therein. A sealing element onthe seal ring is adapted to extend through an opening into a pressurevessel and is expanded by fluid pressure into sealing engagement withinner surfaces of the vessel.

The seal ring assembly comprises an annular stiffener or retainer ring,having an annular shoulder on the outer periphery thereof, allowing theretainer ring to wobble or tilt relative to the receptacle in which itis slidably disposed. A resilient piston, or seal ring, is secured tothe retainer ring, said seal ring having an annular lip adapted to beurged into sealing relation with the inside walls of the skirt of thereceptacle in which the retainer ring and piston are slidably disposed.The retainer ring also has a resilient sealing element secured thereto,in spaced apart relation from the seal ring, said sealing element beingadapted to be urged by fluid pressure into sealing relation with innersurfaces of the pressure vessel about the opening to be sealed while theretainer ring is urged into sealing relation with outer surfaces of thevessel about the opening.

A plurality of anchor members, having downwardly converging surfaces onlower portions thereof, are disposed in sliding relation with slip ringsegments having complementary inclined surfaces such that forces exertedthrough the anchor members longitudinally of a portion of the vessel aretranslated into transverse forces urging the slip ring segments intofrictional engagement with the outer walls of the vessel. The surfacesof the slip ring which are in engagement with the outer walls of theconduit have a high coefficient of static friction.

A primary object of the present invention is to provide an improvedclosure for pressure vessels wherein a seal is urged against both innerand outer surfaces about an opening in a pressure vessel, or othercontainer, wherein the seal is actuated and uniformly applied byinjecting pressure into the pressure vessel, container or conduit topositively close the opening, and wherein the greater the injected thepressure, the tighter the seal is applied.

Another object of the invention is to provide an improved closure forpressure vessels which provides means for sealing about an openinghaving rough irregular surfaces thereabout in a pressure vessel whichmay be easily and quickly applied over and about the opening, and whichmay be easily and quickly removed therefrom.

Another object of the invention is to provide an improved closure forpressure vessels which provides means for sealing over and about anopening in a pressure vessel to be tested which is adaptable andc0nformable to different types of openings, for example, openingsthrough an extension or standpipe secured about the opening of a tank oropenings through the wall of a pressure vessel.

Still another object of the invention is to provide an improved closurefor pressure vessels in which the seal has lower surfaces conformable toinner and outer surfaces of the vessel about the opnning.

A still further object of the invention is to provide an improvedclosure for pressure vessels adapted to grippingly engage the walls ofpressure vessel to detachably secure the closure relative to the vessel.

Other and further objects of my invention will become apparent from thedetailed description hereinafter following and the drawings annexedhereto.

DESCRIPTION OF THE DRAWING Drawings of a preferred embodiment of theinvention are annexed hereto so that the invention may be better andmore fully understood, in which:

FIG. I is a plan view of the closure apparatus;

FIG. II is a cross-sectional view taken substantially along line II-IIof FIG. I;

FIG. III is a cross-sectional view taken substantially along lineIII-III of FIG. II;

FIG. IV is a cross-sectional view taken substantially along line IV-IVof FIG. II;

FIG. V is a cross-sectional view taken substantially along line V-V ofFIG. II;

FIG. VI is a fragmentary perspective view of a seal element;

FIG. Vll is a cross-sectional view taken along line VII-VII of FIG. I;and

FIG. VIII is a fragmentary perspective view ofa modified form of theseal ring.

Numeral references are employed to designate like parts throughout thevarious figures of the drawings.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIGS. I and II of thedrawing, the numeral 1 designates an inlet connection of a pressurevessel, pipe, conduit, tubular member, or other container, having apassage 2 formed therein.

Such inlet connection is normally provided on pressure vessels used forstoring and dispensing liquefied petroleum gas, such as butane orpropane, and sometimes includes an annular flange (not shown) about theupper end thereof through which are provided spaced stud receiving holesfor attachment to a corresponding flange on a control head (not shown)mounted above same. Such control head normally provides a mounting fordispensing outlet, control valves, a pressure gauge, safety valve andother control devices normally required for connecting with suchequipment. Other connections besides a control head could be attached tothe inlet connection 1 such as a conduit having a correspondingconnector thereon.

It will be understood that such type of inlet connection is merely forillustration purposes and that the invention described and claimedherein can be employed with different types and shapes of tank outlets.

The closure apparatus, generally designated by the numeral 4, ispositioned to engage and seal against the surface 6 of inlet connection1 around passage 2 which extends therethrough.

-A dome-shaped cover 8 forms a receptacle having a passage 9 in theupper side thereof which is normally closed by a suitable plug 9a. Thepassage 9 provides an opening for bleeding or flushing air out of thetank or conduit before it is closed for testing. After the pressurevessel is thus flushed out the plug may be secured in the passage 9 toprovide a leak-proof closure during the testing operation. A suitablesource of pressurized fluid may be connected through a pipe 10 andpassage 9b with the passage 2 if it is deemed expedient to do so fordelivering pressurized fluid thereinto.

The dome-like cover 8 includes an annular downwardly extending skirtportion 8a which has formed on its inner side an annular recess 21 forreceiving the seal ring assembly 16. Preferably the inner surface 21a ofthe recess 21 is machined and finished to provide a smooth surface forreceiving the seal hereinafter described.

Furthermore, it will be noted that the width of recess 21 is greaterthan the width of flange 18 of seal assembly l6 and greater in widththan the shoulder 24 on the outer periphery of stiffener or retainerring 12, hereinafter more specifically described, so that the sealassembly 16 can move up and down to act as a piston in response tovariations of pressure within the dome 8.

Seal ring assembly 16 comprises a stiffener ring 12, a resilient pistonor seal ring 14 carried by the stiffener ring 12; seal means, such asgasket 19 carried by stiffener ring 12; and a sealing element 20.

Stiffener ring 12 is preferably of rigid construction and has a recess22 formed in a lower portion thereof arranged to form a shoulder 24around the periphery of stiffener ring 12.

Stiffener ring 12 has passages 26 extending therethrough, said passagesforming a fluid connection between the passage 2 in inlet connection 1and the inside of dome shaped cover 8 above piston assembly 16.

The central portion 28 of stiffener ring 12 has an opening 30 formedtherein through which suitable means, such as stem 40, to urge the sealring assembly toward the end surface 6 on inlet connection 1 may beconnected as hereinafter more fully explained.

The resilient piston or seal ring 14 is preferably made of resilientmaterial, such as neoprene or rubber compound, and includes an upwardlyextending annular lip 17 and flange 18 being preferably, but notnecessarily, disposed in right angular relationship with reference tothe outer surface 17a. The flange 18 is secured to stiffener ring 12 toprovide relnforcement to prevent undue extrusion of resilient materialinto passage 2 of inlet connection 1 and through any openings which maybe formed in or around the surfac 6 against which seal assembly 16 isurged. The seal ring 14 might also be made of flexible, relativelypliable metal or other material which would provide a seal, such asaluminum, asbestos composition, Teflon, and the like.

To facilitate accomplishing a seal between the end surface 6 on inletconnection 1 and seal ring assembly 16, seal means, such as gasket 19 issecured to stiffener ring 12. The degree of resiliency and thickness ofthe gasket 19 is, to some extent, dependent upon the size, shape, androughness of surface 6 of inlet connection 1. If the end of connection 1is smooth and relatively flat, gasket 19 is preferably constructed ofresilient material. However, if the end is rough or has sharp edges,gasket 19 is preferably constructed of a harder less resilient metallicmaterial.

The sealing element 20, best illustrated in FIGS. II and VI, isparticularly adapted to extend into the opening 2 in inlet connection 1such that fluid pressure urges same into sealing engagement with innersurfaces 2b of the connection.

The outer lip 20a of element 20 preferably has a tapered cross-sectionarranged to form a sharp lower edge 2012 which can be readily deflectedto facilitate insertion thereof into opening 2. The tapered lip 20a,

constructed of resilient material such as neoprene or rubber, is pliableand urged into intimate contact with surface 2b inside the inlet opening2 even at low fluid pressure, for example as pressure is increasingwhile fluid is being injected.

To accomplish an initial seal when pressure inside and outsideconnection 1 are substantially equal, the circumference of the peripheryof element adjacent the edge 20b is preferably slightly greater than theinside diameter of opening 2. The circumference of the element 20adjacent the opposite end 200 thereof is substantially equal to that ofthe opening 2. It should be appreciated that the outer surface 20d,therefore, resembles that of a truncated chonical member and that whenlip 20a is positioned in opening 2, the edge 20b is biased intoengagement with the surface 2b.

Sealing element 20 preferably is not rigidly connected to stiffener ring12 because it is generally desirable to position element 20 asillustrated in FIG. II prior to securing the receptacle 4 to inletconnection 1. Therefore, a second tapered lip 20d on element 20 isarranged to seal against the face of stiffener ring 12. Lip 20d extendsarcuately inwardly about the end 200 of element 20 and the edge 20e isbiased into sealing relation with the face of stiffener ring 12 beforeseal ring assembly reaches the position illustrated in FIG. II.

In the particular embodiment of the device illustrated the gasket 19 isbonded to sealing element 20. However, it should be appreciated that ifgasket 19 is to be constructed of resilient material the gasket 19 andelement 20 can be formed as a single element by molding or extrusionprocesses. It also should be readily apparent that lip 20a and lip 20dcan be separate elements so long as the required sealing isaccomplished.

In the embodiment of the invention illustrated in FIG. ll of thedrawing, the resilient piston 14 is secured to stiffener ring 12 bythreaded bolts 31 which extend through apertures in back-up member 32and through apertures in flange 18 of seal ring 14 to threadedly engagethreaded holes in stiffener ring 12.

A modified form of the seal ring is illustrated in FIG. VIII wherein astiffener ring 112 has an annular groove 113 formed about the upperperiphery thereof to receive the ring 114. Seal ring 114 has taperedouter lips 117 urged by fluid pressure into sealing relation with theinner surface 21a of the skirt 8a of receptacle 4 and into'sealingrelation with side 113a of groove 113. A shoulder 113b extends aboutgroove 113 limiting movement of'ring 114 relative to stiffener ring 112in an axial direction. A recess 122 is formed about the lower portion ofstiffener ring 112, as viewed in FIG. VIII, providing a guiding surfaceor shoulder 124 to permit alignment of stiffener ring 112 with the endsurface of pipe 1.

A conventional bonnet 34 extends through and is rigidly connected to, acentral portion of dome 8. Bonnet 34 has a threaded bore 36 threadedlyengaging threads 38 on the rising stem 40. Stem 40 has a hand wheel 42at the upper end thereof whereby rotation of the hand wheel 42 rotatesstem 40 thereby moving said stem axially relative to dome 8.

Suitable packing material 44 is disposed about stem 40 to preventleakage therearound.

Stem 40 has a reduced portion 46 at the lower end thereof which extendsthrough opening 30. Washers 48 and 50 are positioned on opposite sidesof the central portion 28 of stiffener ring 12 and are secured on thelower end of stem 40 by a nut 54 which threadedly engages the end ofstem 40. It will be noted that a space 46a is provided between washers48 and 50 and transversely extending central portion 28, allowing sealring assembly 16 to move and float vertically toward and away fromsurface 6 on inlet connection 1. When pressure is applied within passage2 of inlet connection 1, the seal ring assembly 16 acts like a pistonand moves toward surface 6 to form a positive seal thereagainst.

Stem 40 facilitates positioning seal ring assembly 16 and prevents itfrom falling out while cover 8 is being placed over passage 2, while thecap 4 is being trans ported, or while it is in storage.

Stiffener ring 12, having a tapered or relieved recess portion 22forming a shoulder 24 adjacent the upper edge thereof, allows stiffenerring 12 and seal ring 14 to float freely to conform to the configurationof the surface 6 of inlet connection 1, thereby preventing sticking orwedging in the event seal ring assembly 16 is tilted out of a planeperpendicular to the axis of the passage 2.

Recess 22 also compensates for slight deformation of retainer ring 12when high pressure is applied thereto.

The outer surface 17a of lip 17 is preferably flat and closely conformsto the inner surface 21a of the recess 21 provided on the inner side ofskirt 8a of cover 8.

Suitable means for securing the dome-shaped cover 8 to the inletconnection 1 of a pressure vessel comprises means, such as anchormembers 60 and slip ring segments 62, for translating force exertedagainst the cover 8, tending to move said cover away from the surface 6of inlet connection 1, into a force directed transversely of thelongitudinal axis of the inlet connection 1 to grippingly engage theouter surface of the inlet connection 1.

In the particular embodiment of the invention illustrated in thedrawing, anchor members 60 comprise legs 60a, 60b, 60c, 60d, 60e and 60fspaced equidistantly about the periphery of receptacle 8. Preferablythere should be at least three such spaced legs welded or otherwisesecured to cover 8 to provide uniform sealing about the passage 2.However, such seal could be provided by two or more such legs spacedthereabouts and in the illustrated embodiment six legs are employed.

Each leg 60a-60f is secured to the skirt 8a of cover 8 and extendsdownwardly therefrom. The lower end of each of said legs is turnedinwardly at its lower end to provide a hook-like member 64.

As best illustrated in FIG. II of the drawing, hook portions 64 on thelower ends of legs 60a-60f have shaped, tapered, downwardly convergingsurfaces 66 formed thereon.

Slip ring assembly 62 is preferably formed in segments 62a, 62b, and62c.

Each of the segments 62a, 62b, and 620 has outwardly extending lugs 68aand 68b welded or otherwise secured to opposite ends thereof, each ofsaid lugs having an aperture 69 extending therethrough. The slip ringsegments are secured together by connectors such as bolts 70 whichextend through apertures 69 in lugs 68a and 68b on the respectivesegments.

As best illustrated in FIGS. IV and V .of the drawings, spaces 71 areprovided between the ends of the respective segments 62a, 62b and 62csuch that tightening of nuts 72 on threaded bolts 70 urges the segmentsinto gripping engagement with the outer surface of inlet connection 1.It should be noted that connectors 70 do not restrict movement of ringsegments 62a, 62b, and 62c inwardly. However, springs 71a are positionedabout bolts 70 to bias the segments toward a position wherein thesegments disengage inlet connection 1 to maintain the segments in astationary condition while cover 4 is being positioned over opening 2.

Each of the segments 62a, 62b, and 620 has an inclined surface 76 on theback side thereof which is disposed in sliding relation with inclinedsurface 66 on the lower ends of legs 6011-60 Referring to FIG. ll of thedrawing, it should be readily apparent that the inclination of surfaces66 and 76 cause abrasive surfaces 75 on each of the segments 62a, 62b,and 62c to be urged into gripping relation with inlet connection 1 whena force is applied to cover 8, tending to separate said cover from inletconnection 1.

In the embodiment of the invention illustrated, the abrasive surface 75is rough, having teeth 75a formed therein. However, it should beappreciated that an abrasive lining material (not shown) could beemployed in lieu of teeth 75a.

When pressure inside cover 8 exerts a force tending to separate saidcover from inlet connection 1 a force equal and opposite to that exertedby legs 60a, 60b and 60c upon slip ring segments 62a, 62b, and 62c isexerted outwardly on legs 60a-60f tending to bend them outwardly.Therefore, to prevent bending of the legs 60a60f outwardly, suitablemeans such as ring 80, is provided thereabout to prevent deformation ofsaid legs. Ring 80 is welded or otherwise rigidly secured to the lowerends of legs 60a-60f.

From the foregoing it should be readily apparent that inclined surfaces66 on legs 6011-60f form a cup or socket having a cross-sectional areawhich decreases downwardly for receiving a substantially conical shapedslip ring assembly 62.

OPERATION The operation and function of the device hereinbeforedescribed is as follows:

To connect the closure assembly 4 to the inlet con nection l of atubular member, nuts 72 on bolts 70 which secure slip ring segments 62a,62b, and 62c together are loosened to allow the abrasive surfaces 75 onsaid slip rings to encircle and engage the outer wall of tubularmember 1. Nuts 72 are then tightened.

Hand wheel 42 is then rotated to urge seal ring assembly 16 downwardlyinto sealing engagement with surface 6 about passage 2 of tubularmember 1. This establishes an initial seal and removes slack betweeninclined surfaces 66 and 76 on legs 60a-60f and slip ring segments 62a,62b, and 62c, respectively, It will be noted that this operation isquickly, simply, and easily carried out.

The plug 9a is then removed to flush air from the tank after theinjected pressure fluid is connected to the inside of tubular member 1.The plug 9 is then replaced and the liquid or gas pressure is applied tothe interior of the tank or pressure vessel to test same.

Such injected pressure acts upon the upper surface of seal ring 14 toforce flange 18 against the upper surface of stiffener ring 12, sealingtherebetween while simultaneously urging stiffener ring 12 and sealmeans 19 into sealing engagement with outer surface 6 about passage 2 intubular member 1. The injected pressure also acts upon the inner surface17b of lip 17 to urge the outer surface 17a of lip 17 into sealingengagement with the inner surface 21a of recess 21 formed in the skirt8a of the cover 8 to press such surface into sealing engagement. Ashereinbefore described lips 20a and 20d of element 20 seal against theface of stiffener ring 12 and the inside wall 2b of tubular member 1.

The greater the pressure applied internally of the pressure vessel 1 themore positive and secure the seal is. It should also be noted that thegreater the pressure applied internally of the pressure vessel the morepositive the gripping action of seal ring segments 62a, 62b, and 62c.The seal about passage 2 in tubular member 1 in uniformly applied alongboth the surface 6 and 21a to provide a uniform seal without areas ofleakage.

As hereinbefore pointed out, a source of pressurized fluid may beconnected through a suitable conduit 10, best illustrated in FIG. II, todeliver pressurized fluid to the inside of closure assembly 4.

It should be readily apparent that other and further embodiments of theinvention may be devised without departing from the basic concept of myinvention.

Having described my invention I claim:

1. Means for sealing about a passage through a wall of a vesselcomprising, a seal ring receptacle, said receptacle having an annularskirt portion; anchor means secured to said receptacle to secure saidreceptacle relative to the vessel; a piston slidably disposed in the receptacle, said piston having an aperture extending therethrough andhaving a surface area acted upon by pressure in the receptacle which isgreater than the surface area acted upon by fluid in the vessel suchthat fluid pressure in the receptacle urges said piston toward the wall;a first lip on said piston arranged to be urged by fluid pressure intosealing engagement with an inner surface of the annular skirt portion ofthe receptacle; and a second lip on said piston positioned to extendthrough an opening in a vessel when the piston is posi tioned inengagement therewith and arranged to be urged by fluid pressure intosealing engagement with an inner surface of the vessel.

2. The combination called for in claim 1 wherein the anchor means hastapered surfaces thereon; and with the addition of slip ring segmentspositionable about a portion of the vessel, said segments having taperedsurfaces thereon slidably engageable with the tapered surfaces on theanchor means.

3. The combination called for in claim 1 with the addition of meansbetween the receptacle and the piston to urge the piston toward asurface about the passage.

4. The combination called for in claim 3 wherein the means to urge thepiston toward a surface about the passage comprises a stem movablethrough an aperture in the receptacle; and with the addition of means tosecure the stem to the piston.

5. The combination called for in claim 1 wherein the piston comprises anannular stiffener ring made of nonresilient material and having anannular recessed area about one end thereof, providing an outwardlyextending shoulder about the other end thereof; a resilient seal ringcarried by the stiffener ring, said resilient piston including anupwardly projected annular lip substantially co-extensive with the outersurface of the shoulder.

6. The combination called for in claim 5 wherein the resilient seal ringis mounted on the inner end of the stiffener ring.

7. The combination called for in claim 2 with the addition of abrasivemeans on the inner side of the slip ring segments engageable with anouter wall of the vessel.

8. The combination called for in claim 7 wherein the abrasive meanscomprises teeth formed on at least one of the slip ring segments.

9. The combination called for in claim 2 with the addition of meanssecured to the anchor means to prevent deformation of said anchormembers.

10. Means for sealing about a passage in a vessel comprising, a sealring receptacle, said receptacle having an annular skirt portion; a sealring assembly slidably disposed in the receptacle, said seal ringassembly having an aperture extending therethrough and having surfacesthereon arranged to be urged into sealing engagement with an innersurface of the skirt portion of the seal ring receptacle and with anouter surface of the vessel; sealing means secured to said seal ringassembly adapted to extend into the passage in the vessel and arrangedto be urged into sealing engagement with an inner surface of the vessel;spaced anchor members depending from said skirt portion; inter-engaginggripping means connectable between the anchor members and the vesselarranged to grippingly engage the outer wall of the vessel whereby fluidpressure in the vessel urges the seal ring assembly into sealingengagement relative to the outer wall of the vessel about the passageand with the skirt of the receptacle,urges the sealing means intosealing engagement with the inner wall of the vessel, and causes theinterengaging means to grip the outer wall of the vessel.

11. An article of manufacture comprising, an annular stiffener ring; anannular shoulder on the outer periphery of the stiffener ring; a firstresilient annular lip secured to the stiffener ring, said resilient lipprojecting outwardly from one side of said ring adjacent said shoulder;and a second resilient annular lip secured to an opposite side of saidring and axially aligned with said first lip.

12. The combination called for in claim 11 with the addition ofresilient seal means on the stiffener ring circumferentially disposedabout said second annular lip.

13. The combination called for in claim 12 wherein the seal means is agasket.

14. The combination called for in claim 11 wherein the stiffener ringhas an opening extending through a central portion thereof.

15. Means for closing an opening in a pressure vessel comprising, asegmented slip ring assembly positionable to frictionally engage aportion of the pressure vessel; seal means positionable adjacent theopening in the pressure vessel, said seal means having a passageextending therethrough; a receptacle positionable about the seal ringassembly; and anchor means secured relative to the receptacle andengageable with the slip ring assembly such that internal fluid pressurein the pressure vessel urges the seal ring assembly into sealingengagement with inner surfaces of the pressure vessel around the openingtherein, and simultaneously urges the receptacle away from the pressurevessel to cause the slip ring assembly to frictionally engage a portionof the pressure vessel.

16. The combination called for in claim 15 with the addition ofresilient means secured to said slip ring assembly arranged to biassurfaces thereon out of frictional engagement with the vessel.

17. The combination called for in claim 16 wherein the slip ringassembly comprises a plurality of ring segments having ends securedtogether; and wherein the resilient means is positioned to urge adjacentends of the ring segments in opposite directions.

1. Means for sealing about a passage through a wall of a vesselcomprising, a seal ring receptacle, said receptacle having an annularskirt portion; anchor means secured to said receptacle to secure saidreceptacle relative to the vessel; a piston slidably disposed in thereceptacle, said piston having an aperture extending therethrough andhaving a surface area acted upon by pressure in the receptacle which isgreater than the surface area acted upon by fluid in the vessel suchthat fluid pressure in the receptacle urges said piston toward the wall;a first lip on said piston arranged to be urged by fluid pressure intosealing engagement with an inner surface of the annular skirt portion ofthe receptacle; and a second lip on said piston positioned to extendthrough an opening in a vessel when the piston is positioned inengagement therewith and arranged to be urged by fluid pressure intosealing engagement with an inner surface of the vessel.
 2. Thecombination called for in claim 1 wherein the anchor means has taperedsurfaces thereon; and with the addition of slip ring segmentspositionable about a portion of the vessel, said segments having taperedsurfaces thereon slidably engageable with the tapered surfaces on theanchor means.
 3. The combination called for in claim 1 with the additionof means between the receptacle and the piston to urge the piston towarda surface about the passage.
 4. The combination called for in claim 3wherein the means to urge the piston toward a surface about the passagecomprises a Stem movable through an aperture in the receptacle; and withthe addition of means to secure the stem to the piston.
 5. Thecombination called for in claim 1 wherein the piston comprises anannular stiffener ring made of non-resilient material and having anannular recessed area about one end thereof, providing an outwardlyextending shoulder about the other end thereof; a resilient seal ringcarried by the stiffener ring, said resilient piston including anupwardly projected annular lip substantially co-extensive with the outersurface of the shoulder.
 6. The combination called for in claim 5wherein the resilient seal ring is mounted on the inner end of thestiffener ring.
 7. The combination called for in claim 2 with theaddition of abrasive means on the inner side of the slip ring segmentsengageable with an outer wall of the vessel.
 8. The combination calledfor in claim 7 wherein the abrasive means comprises teeth formed on atleast one of the slip ring segments.
 9. The combination called for inclaim 2 with the addition of means secured to the anchor means toprevent deformation of said anchor members.
 10. Means for sealing abouta passage in a vessel comprising, a seal ring receptacle, saidreceptacle having an annular skirt portion; a seal ring assemblyslidably disposed in the receptacle, said seal ring assembly having anaperture extending therethrough and having surfaces thereon arranged tobe urged into sealing engagement with an inner surface of the skirtportion of the seal ring receptacle and with an outer surface of thevessel; sealing means secured to said seal ring assembly adapted toextend into the passage in the vessel and arranged to be urged intosealing engagement with an inner surface of the vessel; spaced anchormembers depending from said skirt portion; interengaging gripping meansconnectable between the anchor members and the vessel arranged togrippingly engage the outer wall of the vessel whereby fluid pressure inthe vessel urges the seal ring assembly into sealing engagement relativeto the outer wall of the vessel about the passage and with the skirt ofthe receptacle, urges the sealing means into sealing engagement with theinner wall of the vessel, and causes the interengaging means to grip theouter wall of the vessel.
 11. An article of manufacture comprising, anannular stiffener ring; an annular shoulder on the outer periphery ofthe stiffener ring; a first resilient annular lip secured to thestiffener ring, said resilient lip projecting outwardly from one side ofsaid ring adjacent said shoulder; and a second resilient annular lipsecured to an opposite side of said ring and axially aligned with saidfirst lip.
 12. The combination called for in claim 11 with the additionof resilient seal means on the stiffener ring circumferentially disposedabout said second annular lip.
 13. The combination called for in claim12 wherein the seal means is a gasket.
 14. The combination called for inclaim 11 wherein the stiffener ring has an opening extending through acentral portion thereof.
 15. Means for closing an opening in a pressurevessel comprising, a segmented slip ring assembly positionable tofrictionally engage a portion of the pressure vessel; seal meanspositionable adjacent the opening in the pressure vessel, said sealmeans having a passage extending therethrough; a receptacle positionableabout the seal ring assembly; and anchor means secured relative to thereceptacle and engageable with the slip ring assembly such that internalfluid pressure in the pressure vessel urges the seal ring assembly intosealing engagement with inner surfaces of the pressure vessel around theopening therein, and simultaneously urges the receptacle away from thepressure vessel to cause the slip ring assembly to frictionally engage aportion of the pressure vessel.
 16. The combination called for in claim15 with the addition of resilient means secured to said slip ringassembly arranged to bias surfaces thereon out oF frictional engagementwith the vessel.
 17. The combination called for in claim 16 wherein theslip ring assembly comprises a plurality of ring segments having endssecured together; and wherein the resilient means is positioned to urgeadjacent ends of the ring segments in opposite directions.